Basic Pharm Flashcards
(27 cards)
The dose-response curve is ….
Determined by receptor bonding characteristics and can determine the ED50
Activation of opioid receptor leads to …
Decrease release of neurotransmitters ( increasing K and decreases Ca conductance, neuron becoming hyperporalized and decreases neurotransmitters)
Which opioid receptor responsible for respiratory depression?
Mu 2
Mu1: muscle rigidity
Sigma; hallucinations and dysphoria
Which the only opioid causes decrease myocardial contractility
Meperidine
Acts like atropine; increases HR, decreases contractility, and mydriasis.
Mechanism of Opioid effect on Respiratory depression?
Through blunting CO2 responsiveness (increase apnea thereshold) leading to decrease RR that decreases minute ventilation
The effect are through CNS (decrease central drive to breath).
Respiratory depression will return within …. hours after reversal nalaxobe given
2 hours, it’s even sooner with mini-doses 0.4-1 mg
Alfentanil vs fentanyl I’m onset?
Alfentanil way faster because it’s the only opioid that is weaker base (pKa 6.8 where the other all above 7.4) resulting in 90% ionized and able to cross BBB rapidly.
Plasma-brain equilibrium t1/2 is 1 minute (fentanyl 6.4 minutes)
Sufentanil vs fentanyl?
Both synthetic with very lipid soluble and high protein bound
POTENCY
Fentanyl ~100 times as potent as morphine where sufentanil is just 10 times as potent as fentanyl (way more potent ~1000 compared to morphine)
Potency of opioids compared to morphine ?
Sufentanil (1,000) > Remi (300) > fentanyl (100) > Alfentanil (10) > morphine (1) > meperidine (0.1)
The numbers are relative potency compared to morphine
What explains that fentanyl has faster onset but it’s t1/2 elimination longer than morphine or all other long acting
Lipid solubility is higher and high volume distribution from central compartments to fat and muscles this terminating it’s effect.
Also it has more protein binding than the other long acting opioids which both delays its elimination
Normepridine accumulation in CNS and causes seizures with patients who have coexisted diseases of
Renal failure
3 non SSRI meds can cause sweet onion syndrome
Tramadol
Meperidine
Methadone
How acetaminophen causes hepatic dysfunction
When acetaminophen is taken in normal doses, it is conjugated in the liver to harmless glu- curonide and sulfate metabolites. These meta- bolic pathways become easily overwhelmed in the setting of a large overdose, however. If this occurs, the cytochrome P450 system directs conversion of the excess acetaminophen to a compound called NAPQI, which is conjugated with glutathione to form a nontoxic mercap- turate metabolite. Once glutathione stores are exhausted in the liver, however, the excess NAPQI combines with proteins within hepatic cells causing hepatic cell death. Taurine is a mercaptan-containing amino acid involved in bile acid biochemistry. Citrulline aids in the detoxification and elimination of ammonia. Ornithine plays an important role in the urea cycle. (Katzung, 2004, p. 36)
N-acetylcysteine should be administered as promptly as possible for treatment of aceta- minophen overdose. It works by helping restore hepatic glutathione stores and by pro- viding sulfhydryl groups that bind toxic metabolites. N-acetylcysteine is administered orally in the form of an initial loading dose (140 mg/kg) followed by 17 doses (70 mg/kg each) given every 4 hours.
Dosage equivalent to
(…) Cortisol = hydrocortisone = sole cortisol
(…) Prednisone
(…) Medrals (solumedral)
(…) Dexamethasone
20 C
5 P
4. M
1 D
BB selectivity
A-M (B1)
N-Z (B2)
The 2 non selective B and alpha are (carvedilol and labetalol) which they do not have the typical ending suffixes of -olol
Medications prolong QT mnemonic
“Some Risky Meds Can Prolong QT”
Satalol Resperidone Marcrolides Chloroquine PPI Quinidine Thiazides
Physostigmine or pyridostigmine that corsses BBB and treat Atropine overdose?
Physo phyxes atropine overdose
The physo phyxes it
PyRIDostiGMine “gets RID of Mysthenia Gracie”
G-protein-linked 2nd messenger mnemonic
HAVe 1 M&M3 all cases the Cs
H1 Alpha 1 V1 M1 And M3
Work on Gq -> phosphlipase C -> either increase Ca or + protein kinase C -> smooth muscle contraction
All rest other receptors (b1&2, D1, H2, V2, M2, alpha 2, and D2) stimulates either Gs or Gi and dose all the As (Adenylyl cyclase -> ATP to cAMP -> protein kinase A -> increase Ca in heart)
For whether Gs oR Gi remember mnemonic MAD2 (M2, alpha2, D2 -> Gi)
Alpha 1 vs 2 function
- Vascular SM contraction
- Mydriasis
- Intestines and bladder sphincter contraction
Alpha 2
- decrease SNS
- decrease insulin release
- decrease lipopysis
- increases plt aggregation
Beta 1 vs 2 function
- Tachy and increase conrtactility
- increases renin release
- increases lipolysis
Beta 2
- also Tachy and increase contractility
- lipolysis as well
- vasodilation
- bronchodilator
- increases insulin release
- decrease uterine tone (tocolysis)
- ciliary ms relaxation
- increases aqueous humor production
Efficacy vs potency
Efficacy is the maximum effect of a drug. It does not depend on dose.
Potency is the relative dose required to achieve a given effect and is related to receptor affinity.
The potency of a partial agonist may be higher than that of a full agonist. The efficacy of a partial agonist cannot be higher than that of a full agonist.
What has the largest volume of distribution? Lipophilic or hydrophilic?
Lipophilic drugs with high affinity for tissue components (tissue proteins, tissue lipids) have a large volume of distribution.
Drugs with high degree of plasma protein binding, low degree of tissue protein binding, and hydrophilic nature have a smaller Vd
What is pKa? and what ionized vs nonionized means?
pH which 50% is ionized and 50% is nonionized.
ionized = water soluble nonionized = lipid soluble
if acidic drug introduced into acidic environment, result will be?
nonionized = lipid soluble and therefore its going to be absorbed.
same if basic drug introduced into basic environment, will produce nonionized and will be absorbed.
it only when basic/acidic drug introduced into opposite environment that will produce ionized form = water soluble and therefore will be peed in urine and wont be absorbed.
